Three separate, but related, projects involving alterations in blood cell membranes: 1) We will attempt to elucidate the role of two interacting red cell membrane proteins, actin and spectrin; 2) We will investigate the effect of activated complement (C') components on neutrophil function and distribution and will evaluate pharmacologic methods of blocking excessive neutrophil adhesiveness to pulmonary endothelium; 3) We shall study mechanism of hemolysis in hyperbilirubinemic infants undergoing phototherapy.